This application relates to colchicine compositions for therapeutic purposes, specifically ultrapure colchicine, and methods of making and using the colchicine compositions.
Colchicine, chemical name (−)-N-[(7S,12aS)-1,2,3,10-tetramethoxy-9-oxo-5,6,7,9-tetrahydrobenzo[a]heptalen-7-yl]-acetamide, is a pale yellow powder soluble in water in 1:25 dilution.
Colchicine is an alkaloid found in extracts of certain plants such as Colchicum autumnale and Gloriosa superba. Colchicine arrests cell division in animals and plants. It has adversely affected spermatogenesis in humans and in some animal species under certain conditions.
Gout (or gouty arthritis) is a disease caused by a build up of uric acid due to an overproduction of uric acid or a reduced ability of the kidney to get rid of uric acid. It is more common in males, postmenopausal women, and people with high blood pressure. Heavy alcohol use, diabetes, obesity, sickle cell anemia, and kidney disease also increase the risk. The condition may also develop in people who take drugs that interfere with uric acid excretion.
In gout, monosodium urate or uric acid crystals are deposited on the articular cartilage of joints, tendons and surrounding tissues due to elevated concentrations of uric acid in the blood stream. This provokes an inflammatory reaction of these tissues. Gout is characterized by excruciating, sudden, unexpected, burning pain, as well as swelling, redness, warmness, and stiffness in the affected joint. Low-grade fever may also be present. The patient usually suffers from two sources of pain. The crystals inside the joint cause intense pain whenever the affected area is moved. The inflammation of the tissues around the joint also causes the skin to be swollen, tender and sore if it is even slightly touched. For example, a blanket or even the lightest sheet draping over the affected area could cause extreme pain.
Acute gouty arthritis (alternatively referred to as a gout flare or a gout attack) is a sudden attack of pain in affected joints, especially in the feet and legs. Chronic gout involves repeated attacks of joint pain.
In acute gouty arthritis, symptoms develop suddenly and usually involve only one or a few joints. The big toe, knee, or ankle joints are most often affected. The pain frequently starts during the night and is often described as throbbing, crushing, or excruciating. The joint appears infected with signs of warmth, redness, and tenderness. The attacks of painful joints may go away in several days, but may return from time to time. Subsequent attacks usually last longer. Some people may progress to chronic gout (chronic gouty arthritis), while others may have no further attacks.
If several attacks of gout occur each year, it can lead to joint deformity and limited motion in joints. Uric acid deposits, called tophi, develop in cartilage tissue, tendons, and soft tissues. These tophi usually develop only after a patient has suffered from the disease for many years. Deposits also can occur in the kidneys, leading to chronic kidney failure.
Colchicine can be used for treating adults with acute gouty arthritis and pain in attacks of acute gouty arthritis, and also can be used beneficially for treating adults with chronic gout for prophylaxis of acute gout flares. Although its exact mode of action in the relief of gout is not completely understood, colchicine is known to decrease the inflammatory response to urate crystal deposition by inhibiting migration of leukocytes, to interfere with urate deposition by decreasing lactic acid production by leukocytes, to interfere with kinin formation and to diminish phagocytosis and the subsequent anti-inflammatory response. The anti-inflammatory effect of colchicine is relatively selective for acute gouty arthritis. However, other types of arthritis occasionally respond. It is neither an analgesic nor a uricosuric and will not prevent progression to chronic gouty arthritis. It does have a prophylactic, suppressive effect that helps to reduce the incidence of acute attacks and to relieve the residual pain and mild discomfort that patients with gout occasionally experience. In some instances, non-steroidal anti-inflammatory drugs (NSAIDs) may also be prescribed to relieve pain and inflammation in acute gouty arthritis attacks. Strong painkillers, such as codeine, or corticosteroids may also be prescribed to relieve the pain.
Colchicine is rapidly absorbed from the gastrointestinal tract. Peak concentrations occur in 0.5 to 2 hours. The drug and its metabolites are distributed in leukocytes, kidneys, liver, spleen and the intestinal tract. Colchicine is metabolized in the liver and excreted primarily in the feces with 10 to 20% eliminated unchanged in the urine.
There remains a need for pure forms of colchicine having low levels of impurities for pharmaceutical use to minimize the potential for side effects in patients taking colchicine pharmaceutical products and to minimize the need for costly toxicity testing required for approval of pharmaceutical products comprising conventional colchicine having high levels of individual or total impurities. In particular, there is a need for stable compositions comprising ultrapure colchicine.